DIOPTASE - TANTARA MINE, CONGO

An extraordinary collector's item from the legendary Tantara Mine in Shinkolobwe – a dioptase geode with emerald-green crystals that have solidified like molten glass in a natural cave. This rare copper silicate is among the most sought-after collector's minerals worldwide and displays its characteristic color intensity in its most beautiful form.

The emerald green of the Congo

Dioptase is a hydrous copper silicate that fascinates with its intense emerald-green to turquoise-green color. This color intensity arises from copper ions in the crystal lattice and surpasses the brilliance of many other green minerals.

The crystal cave opens up like a geological theater: hundreds of dioptase crystals cover the geode's inner walls, while the exterior is crisscrossed with crust-like turquoise formations and reddish-orange copper oxide zones. The crystals form trigonal shapes with a characteristic vitreous luster – typical of high-quality dioptase from the Katanga region.

Crystal formation and cavity structure

The centerpiece of the step is a fascinating cavity formation: In the center, a dark geode opens up, its walls densely covered with small dioptase crystals. This three-dimensional structure provides insights into crystal formation and makes the geological processes comprehensible.

The crystals grow in different directions and form bundle-like aggregates. Under light, they unfold their full potential: Each crystal face reflects the light differently, creating a sparkling interplay of light and dark.

PRESENTATION:

The step is presented on a high-quality transparent acrylic stand, which slightly elevates the geode and makes it visible from all sides.

Under direct light, dioptase reveals its full brilliance: the glassy luster of the crystal surfaces reflects the light like cut gemstones. The three-dimensional cavity structure gives the step depth and makes it interesting from all sides.

Ideal for display cases, desks or as the centerpiece of a mineral collection.

TECHNICAL DATA:

• Dimensions (without stand): approx. 5 × 6 × 4 cm (H × W × D)

• Weight (without stand): 203 g

• Mineral: Dioptase (copper silicate)

• Associated mineral: copper oxides (cuprite, tenorite)

• Mohs hardness: 5 (medium hardness)

• Color: Intense emerald green, reddish-brown oxidation zones

• Location: Tantara Mine, Shinkolobwe (Likasi), Katanga, Democratic Republic of Congo

• Special feature: Crystal cave with hundreds of dioptase crystals

• Includes: Transparent acrylic stand

CARE INSTRUCTIONS:

Dioptase has a medium Mohs hardness of 5 and is sensitive to scratches. Protect from direct sunlight (color may fade over time). Dust only with a dry cloth or clean with a slightly damp, soft cloth. Do not immerse in water or treat with harsh cleaning agents.

COLLECTIBLE VALUE & AUTHENTICITY:

We source our exhibits from carefully selected sources: mineral shows, private collections, and direct contacts at mineral sites worldwide. Every piece is checked for authenticity.

Shinkolobwe dioptase is now extremely rare on the market – most specimens are in museums or private collections. The combination of its rarity, perfect crystal formation, and legendary location makes this piece a valuable investment for collectors.

SHIPMENT:

Insured shipping in sturdy packaging. Collection in the Bergisches Land region is possible by arrangement.

If you have any questions about the origin, authenticity or other details, please feel free to contact us before purchasing.